The longer you hold on to a car, the more depreciation it experiences, so from this perspective there is some value in selling in the near future. However, you say yourself that you are delighted with the car, and if you do decide to change it there is a cost in doing so, and if you replace it with a newer car this will experience higher depreciation than your Ibiza - the rate of depreciation decreases for most cars after the first three years.

Buying a car is an expensive process, and from a very simplified perspective the fewer cars you buy, the less money it costs you, and given you are happy with your current car we would suggest sticking with it until you feel the need to change.

Although the SEAT brand will be changing in the future, this will not happen for several years and is unlikely to have a big impact on resale values in the short term at least.